21311237543800 has 48 divisors (see below), whose sum is σ = 49783455005400. Its totient is φ = 8484094550400.

The previous prime is 21311237543789. The next prime is 21311237543861. The reversal of 21311237543800 is 834573211312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 252460615 + ... + 252545014.

Almost surely, 2^{21311237543800} is an apocalyptic number.

21311237543800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311237543800 is an abundant number, since it is smaller than the sum of its proper divisors (28472217461600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21311237543800 is a wasteful number, since it uses less digits than its factorization.

21311237543800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505005856 (or 505005847 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 21311237543800 in words is "twenty-one trillion, three hundred eleven billion, two hundred thirty-seven million, five hundred forty-three thousand, eight hundred".